对Ag/Cu薄膜退火应力的模拟  

Simulation of annealing stress in Ag/Cu thin films

作　　者：安兵[1] 张同俊[1] 袁超[1] 崔昆[1] 

机构地区：[1]华中科技大学模具技术国家重点实验室

出　　处：《材料研究学报》2003年第5期459-465,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金No.59971021;武汉理工大学材料复合新技术国家重点实验室开放基金

摘　　要：采用基片曲率法测量并研究了Ag/Cu薄膜的应力与温度的关系。初始应力为-250MPa压应力,退火后为370 MPa拉应力。采用基于形变机制图的模型模拟了应力与温度关系的实验曲线,结果表明,温度和应力不同,在薄膜内起作用的主要形变机制也不同。可能的形变机制包括位错滑移、幂律蠕变以及扩散蠕变机制。薄膜比块体材料的应变速率低,在同样的应力下应变更加困难。在退火过程中,薄膜内先使应力松弛的是Ag,将Ag各蠕变机制中的激活能提高到块体材料的1.25～1.35倍,模拟曲线与实验曲线符合得很好。The stress-temperature curve of Ag/Cu thin films was studied by substrate curvature technique in a temperature range of room temperature to 500°C. The as-deposited film-stress is -250 MPa, while after annealing, the stress turns to a tensile stress, 370 MPa. A model based on deformation mechanism maps was used for simulating the stress-temperature curve. The results show that the main relaxation mechanisms, which include dislocation glide, power-law creep and diffusion creep, vary with the temperature and stress. However, the strain rates in thin films are smaller than those of bulk materials, making the strain more difficult under the same stress. During annealing, Ag takes the lead in the stress relaxation, and when all of its creep activation energies in films are enhanced up to 1.25-1.35 times of those of Ag bulk materials, the good agreement between simulated curves and measured is obtained.

关 键 词：金属材料 Ag/Cu薄膜 形变机制图 退火残余应力 

分 类 号：TB383[一般工业技术—材料科学与工程]